Heung-Min Son’s hat-trick propelled Tottenham towards their first FA Cup semi-final in five years as they thrashed League One Millwall at White Hart Lane.

It was looking bleak for Spurs early on when Harry Kane’s ankle was caught between Jake Cooper’s legs and the in-form striker limped down the tunnel; replaced by Christian Eriksen.

It turned out to be a positive, at least in the short term, as the Dane opened the scoring after half an hour when he turned Dele Alli’s heavy touch in on the swivel with his back to goal.

Son’s first came ten minutes later when the South Korean was played in down the wing before cutting inside and curling a beauty past Tom King.

Son had his second  ten minutes after half time when Keiran Trippier played him in with a long ball over the top and the stand-in striker volleyed in first time.

Millwall lacked shape and were cut open when Eriksen’s cross found Alli in acres of space to tap in at the back post.

Vincent Janssen was brought on for the goalscorer and scored his first goal from open play for Tottenham when Son found him on the penalty spot and the sub placed his effort into the bottom corner.

Son completed his hat-trick in added time when Janssen stood up a cross to the striker and he volleyed his shot straight at King, but the keeper spilled the shot through his legs and in.

Millwall’s exit from the competition means that the remaining teams in the competition are five of the Premier League’s top six teams.